Filling mechanism for fountain pens



March 14, 1944. D. F, MOHNS FILLING NEcHANIsM FOR FOUNTAIN PENS 2 Sheets-Sheet 1 Filed Aug. l, 1942 @I/ NN Il. N#

,v lli I March 14, 1944. D. F. MoHNs FILLING MECHANI'SM vTS'OR FOUNTAIN PENS 2 Sheets-Sheet 2 INVENTOR.

Filed Aug. l, 1942 Patented Mar. 14, 1944 FLLING' MECHANESM FOR FOUNTAEN PENS Davidl F. Mohns, Janesville, Wis., assignor to The Parker Pen Company, Janesville, Wis., a corporation of Wisconsin Application August 1, 1942, 'Serial No. 453,145

l Claims. (Cl. 1Z0-A7) My invention relates to fountain pens and it has to do particularly with filling mechanisms therefor.

One of the objects of my invention is to provide an improved filling mechanism for fountain pens which is simple in construction, is easy to operate, may be manufactured at low cost, and is adapted to operate at all times with a high degree of eliciency.

Another object is to provide an improved filling mechanism for fountain pens which includes a spring-actuated, short-stroke filling plunger that may be easily operated with one hand.

Still another object is to provide an improved plunger structure for supporting a packing member and which is particularly suited for use in connection with fountain pen filling mechanisms `of the type Awherein the fountain pen barrel serves as an ink reservoir.

A further object is to provide a plunger type filling mechanism for fountain pens of the type wherein the barrel serves as an ink reservoir, in-

cluding a spring-actuated plunger stem carrying a head supporting a soft, pliable packing member, the arrangement being such that, on the forward stroke of the plunger, the packing member is forced into tight sealed engagement with the wall of the pen barrel but is released from the barrel wall on the return stroke so that only a slight spring pressure isrequi'red for rapid reciprocation `of the plunger. Y

An additional object is to provide a unitary filling mechanism of the foregoing character that may readily be applied to andremoved from the peri barrel as a unit.

Otherl objects are to provide a filling mechanism ofv the plunger type which is provided with a thin,

pliable packing member supported in such a manner as to eiect a tight seal on the forward stroke of the filling mechanism with a minimum of frictional drag; and to provide a plunger having a packing supporting head closely approaching the diameter of the barrel wall in which it operates but which permits an unrestricted oW of air or ink, or both, therepast.

Additional objects and advantages will become apparent as this description progresses and by reference to the drawings wherein,

Figure 1 is a side elevational view of one form of fountain pen embodying my invention;

Fig.- 2 is an enlarged longitudinal sectional View taken substantially on line 2--2 ofvFig. 1 and il- Yustrating one form of lling mechanism embodying my invention;

Fig. 3 is a section taken substantially on line 3-3 ofFig. 2;

Fig. 4 is a section taken substantially on line 4 4 of Fig. 2; y

Fig. 5 is a section taken substantially on line 5 5 of Fig. 2;

Fig. 6 is an exploded View of the unitary type filling mechanism shown in Fig. 2; and

Fig. 'l is a partial sectional view of a fountain pen embodying a modified form of filling mechanism embodying my invention.

My invention is well adapted for use in connection with fountain pens of the type disclosed in United States Letters Patent No. 1,904,358, granted on April 18, 1933, to Arthur O. Dahlberg, wherein the barrel of the fountain pen serves as an ink reservoir and filling of the ink reservoir may be accomplished by one hand through the operation of a short, spring-actuatedv plunger reciprocated to effect displacement of air from the reservoir. In the use of a filling mechanism of that type it is required that the spring-actuated movement of the plunger be positive, free and rapid. My invention is particularly concerned with a plunger of the type stated wherein there is employed a plunger-carried head which supports a packing member adapted to engage the reservoirwall of the pen barrel. To the foregoing end I employ a thin, pliable packing member which, on the forward stroke of the plunger, is adapted to effect a tight seal against the reservoir wall but which, on the return stroke of the plunger, is released from the reservoir wall so that the plunger may return to its home position under' the inuence of its actuating spring in a rapid and positive manner. 'Ifhe arrangement is also such that avery slight spring pressure is required to effect this movement.

Referring particularly to the form of my invention shown in Figs. 1 tor, inclusive, of the drawings, I employa pen having a barrel lil, the

A, innerwall of which denes an ink reservoir Il. A, Ink feeding means, generally indicated at I2 and which may be similar to that disclosed in said Dahlberg patent, is mounted in the forward end f of the pen barrellil. It will. be understood,- however, that any other desired-form of feed mechanisrn maywell be employed without departing -from my invention. The ink reservoir ll is site ends of the sleeve.

A A2) with the-plunger packing nut,2|. j l Y l I fj The lower or Vforward face 22a of the plunger head 22 iszconcave and'is adapted to serve as a The plunger type displacement means shown in Figs. 1 t0 6, inclusive, includes a plunger member I3 which is guidingly supported in a tubular packing sleeve I4, the plunger I3 being long enough to extend through and beyond the oppo- Sleeve I4 is externally threaded'at I5 for detachable engagement with a threadedopening'llla in the rear end of the pen barrel |0 (Figs. 2"and 6) and it is provided with Y an annular flange I6 which is adapted to engage a shoulder lb formed by enlarging the outer end of the barrel opening Illa, thereby limiting the extent to which the sleeve I4 may be screwed into and externally threaded extension Il which is adapted to removably receive an end cap I8' (Fig. 2) which conceals the outer projecting end'of so that the complete lling operation is performed with one hand. This action is facilitated by the spring 23 which in this case may be such as to require only a slight pressure to compress the same in moving the plunger I3 inwardly. With the foregoing arrangement, when the plunger is depressed, the packing member 24 is forced into tight sealed engagement with the wall of the'` reservoir II, thereby forcingair from the reservoir I I. Depression of the plunger I3 is followed by release of the same so that the spring can return the plunger to its normal position of -f Fig. 2, the combined depression and release acwith ink.- This action may be accomplished in a free and rapid m-anner due to the fact that, as the plunger I3 moves outwardly, the packingmember the plunger` I3 and prevents accidental actua-Y tion of the same. VThe plunger I3 issupported lows: Within the packing sleeve I4 I mount a piuraiityvof alternating rubber and fe1tfl disks I9 and 2Q, respectively, which have centralA openings through which the'plunger |3fp'a'sses. The

lower or inner end of the packing'sleeve f4 is internally threaded for reception of an adjustable packing nut 2l having an opening 2|a therein through which the plunger I3 passes for guid-v ance.V With this arrangement, byV tightening the packing nut 2| the disks I9 and 2D are expanded into sealed engagement with Vthe Vplunger I3 thereby preventing the escape of ink Yor air past the sleeve I4 and plunger I3. By adjusting the nut 2| the proper engagement of the disks I9 'and 2i! with the plunger I3may be eiected while at the same time permitting free axial movement of the latter. If desired, the felt disks 2|) may contain va lubricant which will aid in the free reciprocation of the plunger I3. I f

The plunger I3 is provided at its inner end with a reducedvthreaded extension |3 uponwhichA is threadedly received a plunger head 22. A The outer end of the plunger I3 is'provided with an Y abutting the head |3b and its other endseatedL in the projecting tubular extensionll of the sleeve I4. This spring is of suchlength that it is confined normally under slight'compression so' that it yieldingly holds the plunger I3 outwardly (Fig. head 22 seated against the seat for apomplementally shapedconcavo-con- `vex packing Vmember 24. The-,packing member 24, which is .ofv slightly greater d iameterfthan the wall ofthe ink reservoirI I, is formed-'of thin, soft rubber or other suitable pliable material.

"The plunger extension I3*i is long enough to project through and beyond the packing member 24 Y within the sleeveV I4 in a sealed manner Vas fol- 24, due to the friction between it and the reservoir Wall, is turned forwardly and freed from lthe Vreservoir wall suflciently to avoid any material sealing action between it and the barrel wall.

'I'he free, rapid return movement of the Vplunger |3,is.ffacilitated, notwithstanding the fact that .tially throughout itsentire surface and any air or ink, or both, that may become trappedbehind the plunger head 22 rwill be freely released past the plunger head and the packing member 24 on the outward movement of the plunger. This ar- .,rangement positively avoids retardation of the plunger movement from the possible -causes'stated. Further, with the foregoing arrangement, it is possible to use a very thinand pliable packing member, thereby greatly reducingI the friction Y between. the packing member and the reservoir stroke of the plunger, a sired displacement.

Jef which is shown iny Fig. 7. speciiicauy.. this wall while positively insuring, on the, forward tight seal to effect the de- Y lVlZy invention may` take various forms, .another 2 form is the'same as that previously described except for the packing unit whichl guidingly lsup- `ports the filling plunger 34.v More particularly,

a'packing sleeve v3|) lsimilar to the sleeve I4 is mountedv in the rear end of thel barrel and this sleeve contains .a plurality of alternating rubber n and felt packinglelemen'ts 3| and 32. AThese elements are retained in place by an end portion '33 which is flxedly securedin placein any desired manner. The plunger 34 is providedwith yfavrerduced extension-35 at its yiorwardfend;and

this reduced extension threadedlyv vreceives" a plungeruhad 35 similar t the plunger head 22 The plunger head supportsa concavo-co'nvex packing member 3'|,"livke the Y packing member 24, whichjissecuredlm place where it receives a retaining nut 25 of consider- Y ably less diameter v,than the plunger head 22 and packing member 24. Theplunger head 22, which is of cylindricalshape, has its lower portion en- In the Vuse of the foregoing structure'htheV pen barrel maybe grasped in one handgand ,the

plunger I3 actuated by the thumbor forenger' by' a retainerj nut 33. In this forni', thefoutward f face of the plunger head 36 isatpsimilarvto the inner end surface of 4,the 'sleeve 'v30n'd,' in I the normal outward position'of. the plunger 34,

Yfthese surfaces engage each ether to seal v,t'l'l'e passageway through the packing sleeve against the l entry of air andinktherethrough inthe Annrmal condition'of `the pen., The packing elements 3|Y and l32 are initially ylocated and compressed vto snugly engage the plunger 34 andthey, as -will be wellunderstood, aid -in preventing jleakage of inkand air at the rear ,end

. .0f-them during periods of filling or otherwise.

I believe that' the operation and advantages 'Ihefilling mechanism embodying my invention is quite simple in con'- struction; it may be manufactured quite'cheaphaving a barrel serving' as an inkreservoir, a

plunger adapted to Vbe reciprocably mounted in the rearend of the barrel, a head having a concave face carried by the inner end of said plunger and of such size that its periphery extends into close proximity to the wall of the ink reservoir, the periphery of said head being provided with axially extending grooves which permit ready passage of ink or air or both past said head, a concavo-convex packing member formed of a thin, pliable material seated against the concave face of said head andbeing of greater diameter than the wall of theink reservoir, and a retaining element also carried by the inner end of said plunger for securing said packing member in place upon said head, said retaining element being of much less diameter than said packing member and head to permit said packing member to free itself from the wall of the ink reservoir on the return stroke of said plunger.

2. In a filling mechanism for a fountain pen having a cylindrical barrel the innerv surface of which serves as an ink reservoir, a plunger adapted to be reciprocably mounted in the rear end of the barrel and having an exteriorly accessible portion and another or inner portion adapted to project into the ink reservoir, spring means associated with the exterior portion of said plunger constantly urging it outwardly, a cylindrical packing head having a concave face on the inner portion of said plunger adapted to engage said sleeve to limit the outward movement of said plunger, said head being of a diameter closely approaching the diameter of the ink reservoir and having a plurality of longitudinal grooves in its periphery to permit ready passage of air or ink or both therepast, a concavo-convex packing member formed of a thin, pliable material seated against the face of said head and being of a diameter greater than the diameter of the ink reservoir, and a retaining member carried by the inner portion of said plunger and being of less diameter than said packing member and head for securing said packing member upon said head, the arrangement being such that said packing member is forced into sealed engagement with the wall of the ink reservoir on the forward stroke of said plunger and on the return stroke of the latter said packing member is moved out of sealed engagement to permit said spring means to freely and rapidly return said plunger to its home position.

3. In a lling mechanism for a fountain Ypen having a cylindrical barrel the inner surface of which serves as an ink reservoir, a plunger adapted to be guidingly supported in the rear end of the barrel and having its end portion extending outwardly and inwardly thereof with its inner end reduced and threaded, a spring disposed between the threaded extension on said sleeve and the outer end of said plunger constantly urging the latter outwardly, a packing head having a threaded opening in which the inner end of said plunger is received, said head being adapted to Vof my invention'will be lwell understood from Vthe foregoing description.

abutsad sleeve to limit the extent of outward movement of said plunger, said head also having a concave face, being cylindrical, being of a 'diameter closely approaching the diameter of the ink reservoir and having its periphery grooved longitudinally .to permit the ready passage of air or ink' therepast, a thin, pliable, concavoconvex packing member of `greater diameter than Vthe ink reservoir seated against-the concave face -of 'said head andy having a central opening throughl'whi'ch the' inner end of -said plunger "passes, and a retaining member carried bythe inner end of Y'saidv plunger and engaging said packing member' to hold the latter aga-instrth'e face of said head, said retaining member perkmitting the periphery of said packing member to fall freely away from the wall of the ink reservoir on the return stroke of said plunger.

4. In lling mechanism for a fountain pen having a barrel serving as an ink reservoir, a plunger mechanism for effecting a displacement within said reservoir for the purpose of drawing ink thereinto, which comprises a plunger stem adapted to be reciprocably mounted in said barrel and having at its forward end a head portion of such size that its periphery is adapted to be disposed in close proximity to the wall of the ink reservoir, a packing element carried by the forward portion of said plunger head and formed of pliable material of greater diameter than the wall of the ink reservoir and so mounted upon the plunger head that upon forward movement of the plunger it effects a sealed engagement with the barrel wall and upon rearward movement of the plunger it is released from the barrel wall to permit free and unrestrained movement of the plunger rearwardly, the peripheral surface of said plunger head being provided with axially extending grooves which permit ready passage of ink or air or both past said head, and spring means lightly opposing forwardmovement of said plunger but of sufficient strength to effect quick rearward movement of said plunger as said packing member is released from the cylinder wall upon such rearward movement.

5. A plunger device for filling mechanism of fountain pens wherein the barrel serves as an ink reservoir, which comprises a plunger stem, a head at the forward end of said stem, the peripheral surface of which is adapted to lie in close proximity to the wall of the ink reservoir, a packing member carried by the forward portion of said head and adapted to engage the reservoir wall and effect a seal between such wall and the periphery of said head upon the forward movement of said plunger and further adapted upon rearward movement of said plunger to be released from said wall to permit free movement of the plunger rearwardly, the peripheral surface of said head having axially disposed grooves therein permitting ready passage of ink or air or both past said head.

6. In a filling mechanism for a fountain pen having an ink reservoir, a plunger mechanism for effecting a displacement within said reservoir for the purpose of drawing ink thereinto which comprises a plungerstem, a head at the forward end of said stem, the peripheral surface of which is adapted to lie in close proximity to the wall of the ink reservoir, a packing member carried by the forward portion of said head and adapted to engage the reservoir wall and effect a seal between such wall and the periphery of said head upon the forward movement of said plunger and further adapted upon rearward movehaving a barrel containingan. ink reservoir, a

plunger adapted to be yreciprocably mounted in the; rear end o1 the barrel, a head having aconvcave face carried by thetinner end of said plung- .-erv andof such size ythat its periphery extends into closerproximityt to the wall of theink reser- `voir, the periphery of said head being provided with axially extending grooves which permit ,ready passage of ink or air or both past said head, `a concaVo-onvex packing member formed of a thin, pliable material seated against the con- 5 cave face offsaid head and being of greater diameter than the wall of the link reservoir, and a retaining element also carried by the inner end of said plunger for securing said packing member in place upon said head, said retaining element 10 being of much less diameter than said packing member and head to permit said packing mem- Vber to free itself vfrom the wall of the ink reseryoir on the return stroke of said plunger.

i Y DAVID F. MOHNS. l 

